Timing control apparatus



Jan. 15, 1946. A, H. POWELL TIMING CONTROL APPARATUS Filed Feb. 10. 1944'2 Sheets-Sheet 1 DEV/CE 70 85 CONTINUED I m/wm W Inventor Alric H.Powell,

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Jan. 15, 1946. A. H, POWELL 2,393,187

TIMING CONTROL APPARATUS Filed Feb. 1o, 1944 2 Sheets-Sheet 2 3*, m l/"Mlll I l2! MAIN TIMER MOTOR C/RCU/7'% Ihvehtor:

AIr-ic H. Powell,

by 792/147 Quinn H is Abborneg Patented Jan. 15, 1946 TIMING CONTROLAPPARATUS Alric H. Powell, Yea'don, Pa., assignor to General ElectricCompany, a corporation of New York Application February 10, 1944, SerialNo. 521,794

Claims.

My invention relates to improvements in timing control apparatus andmore particularly electrical control apparatus for automatically timingeach of a plurality of operations which have to be performed in a givensequence with a deilnite time for each operation. Such operationalsequences occur in various manufacturing processes, for example, themanufacture of gasoline, synthetic rubber, water gas and other products.

For automatic control, many of these processes involve so manyoperational steps that a large number of switching stages would berequired if the timing apparatus were run continuously. Consequently,many contact points would be sacriilced, especially when one or more ofthe series of operations required a relatively long time for completion.This would necessitate an undesirable investment in timing equipmenttogether with large space requirements and excessive maintenance. Toavoid this, it has been proposed to use one or more supplementary orauxiliary timers which are known to the art as dormant timers. These areso arranged as to stop the timing apparatus for operations requiring alon time and then to restart the timing operation upon completion of thelong time operation. In this way, the range of the timing apparatus wasmaterially increased. However, arrangements with which I am familiarrequire the use of so many switching stages that the timing apparatus isnot used tothe best advantage.

Where dormant timers have been used, it has been customary to energizethem and the necessary controls from the source which energizes the maintiming apparatus. If the voltage of this source should fail, even thoughonly momentarily, the dormant timer must not reset on loss of voltage,otherwise there will follow an overtime action in the particular longtime operation under its control. Such overtime action might ruin theproduct or even prove hazardous from the standpoint of possibleexplosions, fire, and so forth. Ofcourse, if the control voltage is of!for any material time, it is necessary to resort to manual control. Butgenerally speaking, the usual loss of voltage is momentary inconsequence of switching surges, momentary overloads and the like on thepower system.

An object of my invention is to provide improved timing controlapparatus wherein the main timing apparatus is arranged to be stopped ata: particular control point or switching stage and maintainedinoperative for the desired time, at the end of which it is againstarted from the same control point. Another object of my invention isto provide a dormant timing control which requires the minimum number ofswitching stages, that is, one. A further object of my invention is toprovide an improved timing control apparatus wherein one dormant timercan be used to stop the main timing apparatus ior any one or more of aplurality of operations, each requiring substantially the same time withno more main timer switching stages required than the number ofoperations to be performed. Still another object of my invention is toprovide improved electrical timing 1 control apparatus wherein momentaryloss 0! voltage or the control source during a dormant timing stage doesnot materially alter the duration of such stage. These and other objectsoi my invention will hereinafter appear in more detail.

In accordance with my invention, I provide, for a main timer having aplurality of control or switching points, a dormant timer control suchthat the main timer can be stopped at any desired switching oint orstage and maintained at such stage for a predetermined time and thenrestarted to continue its normal timin controls. Also in accordance withmy invention, I provide, for an electrically actuated main timer, anonresetting dormant timer control energized from the same source as themain timer so that mo mental-y loss of voltage of the control source issubstantially ineffective to alter the length of the dormant period.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying two sheets ofdrawings, and its scope will be pointed out in the appended claims.

In the accompanying two sheets of drawings, Figs. 1 and 2, when takentogether right edge to left edge, respectively, diagrammaticallyillustrate an electric timing control apparatus enibodying my inventionwith the main timing aparatus shown in Fig. l and the dormant timingapparatus shown in Fig. 2'.

Referring now to Fig. 1', the main timer comprises one or more selectiveswitches 5 for controlling the operation or a. plurality of deviceswhich are to be operated in a predetermined sequence and at intervalswhich depend upon the character of the steps in the process to beperformed. For the urpose oi illustrating my invention, only one device6 is shown and that schematically. The devices may in general beelectrically actuated control elementsor mechanism arranged to beenergized from a suitable source, indicated simply as buses X and Y, forcontrolling and effecting the operation of motors, valves, pumps, etc.,according to the character of the process in question. As shown, eachselective switch 5 comprises a movable circuit controlling member Iwhich is mounted for rotation about the center of concentricallyarranged stationary contacts comprising two spaced ring contacts 8 and 9and twocircular rows of staggered selective contacts I9, |2, |3 and H.For the purpose of illustrating my invention, only a few of theseselective contacts are shown, but it is to be understood that an desirednumber may be provided. Thus, in one embodiment of my invention, thereare about four hundred and fifty selective contacts for each circuitcontrolling member i As shown, the circuit controlling members i are notof themselves conductive, but each carries at one end contacts l6 and IIwhich engage the ring contacts 8 and 9, respectively, and at the otherend contacts |8 and H which engage the contacts m, H, |2, |3, |4, etc.alternately as the circuit controlling member I is turned clockwise. Forcompleting circuits between the ring contacts and the selectivecontacts, the contacts IS and |9 are connected by a conductor and thecontacts I! and I8 are connected by a conductor 2|, both of theconductors 20 and 2| being mounted on the circuit controlling member I.

For rotating the circuit controlling members I at the desired speed, Iprovide an electric motor actuated reducing gear mechanism. As shown,this mechanism comprises a vertical shaft 22 to which are secured bevelpinions 23 in step-down engagement with bevel gears 24 rigidlyassociated with the members At its lower end, the shaft 22 carries abevel gear 25 in engagement with bevel pinions 26 and 21 which arearranged to be driven selectivel by one or the other of two motors 28and 29 acting through reducing gear mechanisms 3-9 and 3|, respectively.Preferably the motors 28 and 29 are of the relatively slow speedself-starting synchronous inductor type, such as disclosed, for example,in United States Letters Patent 2,105,513, issued on January 18, 1938,since such motors start and stop substantially instantaneously and soprovide more accurate timing than is possible with the usual type ofmotor having a direct connected brake. Also,

by using a slow speed motor, the necessary gear ure of a motor or itsassociated gear mechanism or to drive the shaft 22 at one speed whilethe lower circuit controlling member 1 is in operation and at adifferent speed while the upper circuit controlling member] is inoperation and also to operate manually, I provide clutch means such thatthe shaft 22 may be actuated selectively by either of the motors 28 and29 or manually as desired. As shown, this clutch means comprisesshifting levers 32 and 33, respectively pivoted at 34 and 35. Theselevers are simultaneously movable selectivel to shift clutch members 35,31 and 38 which are respectively operable to put the shaft 22 in drivingrelationship with the motor 28, the motor 29 or a manually operable gearmechanism 39 provided with a handwheel 40. For this selective operationof the shifting levers 32 and 33, they aresuitably slotted andinterconnected by a straight crank 4| pivoted at 42, a link .3 and abell crank 44 pivoted at 45. Operation of the bell crank 44 to obtainthe desired driving iii selectivity or clutching action is eifected byturn ing a handle 46 which is secured to a shaft, indicated by thebroken line 41 and rigidly associated with the bell crank.

In order simultaneously to control the energization of the motors 28 and29 and the clutching action, the shaft 41 has rigidly associatedtherewith and insulated therefrom a switching member 48 which isarranged to cooperate with contacts 49 and 50 respectively to controlthe energizing circuits of the motors 28 and 29. In the verticalposition of the handle illustrated, the gear mechanism 30 associatedwith the motor 28 is in driving relationship with the shaft 22 throughthe clutch member 36, and the switching member 48 is in engagement withthe contact 49 in the energizing circuit of the motor 28. If the handle46 is turned clockwise to the position indicated by the broken line 5|,then the gear mechanism 3| associated with the motor 29 is in drivingrelationship with the shaft 22 through the clutch member 31, and theswitching member 48 is in engagement with the contact in the energizingcircuit of the motor 29. If the handle 46 is turned counterclockwise tothe position indicated by the broken line 52, then the manually operablegear mechanism 39 is in driving relationship with the shaft 22 throughthe clutch member 38, and the switching member 48 does not engage eitherof the contacts 49 or 50.

The function of the circuit controlling member and the cooperatingcontacts H], II, l2, etc. is primarily selectivity. Accordingly, sincethe switch structure necessary to provide such selectivity for a largenumber of circuits is restricted by space requirements and portabilityof equipment, it is not feasible to have this structure encompasscircuit making and interrupting functions. In view of this, I providesuitable means, such as an impulse switch 53, for the purpose of makingand interrupting the circuits of devices to be controlled, such as thedevice 6. As shown, the impulse switch 53 is of a rotary control type,examples of which are well known in the art, and comprises two rotatableswitching arms 54 and 54' which, for correct timing, are mounted on andinsulated from a shaft 55 driven directly from the shaft 22 throughbevel gears 55. The switching arms 54 and 54' are arranged to cooperaterespectively with the lower and the upper circuit controlling membersFor this purpose and in order to obtain maximum length of service, eachswitching arm 54 and 54 is arranged to cooperate with a plurality ofparallel connected stationary contacts 51 and a plurality of stationarycontacts 58 so arranged that each switching arm alternately engages acontact 51 and a contact 58. The construction and arrangement of theimpulse switch 53 is such that when either of the circuit controllingmembers I is in the middle of a stationary contact segment H], H, l2,etc., the cooperating impulse switch contact closes and completes anelectrical circuit to the contact segment as will appear in more detailhereinafter.

In order to avoid circuit controlling operations by one circuitcontrolling member I while the other circuit controlling member I isgoing through its active operational sequence, particularly when bothcircuit controlling members are required to complete a series ofoperations, I provide suitable means, such as a transfer switch 59,which, as shown, is arranged to be operated by the lower circuitcontrolling member-'1 every time this member makes a complete rotation.

moans-z This switch 59, as illustrated, is of the overcenter stay-puttype and comprises a. doublethrow contact arm 68 pivotally supported atEl and arranged to connect an incoming conductor 82 to the impulseswitching arm 54; through contacts 63 and a conductor. to the switchingarm 54" through contacts 85 and a conductor 66. The double-throw contact60 is actuatedby a movable yielding member 61 which rides on one side orthe other of a suitably shaped cam 68 to tip the arm 6| as the lowercircuit controlling member 1 rotates clockwise into engagement with anoperating lever 89 pivoted at I and arranged to raise the member 61againstthe. bias of a spring H. As soon as the lower circuit controllingmembar 1 moves by the end of the arm 6.9, the spring H forces the memberit! downward to actuate the switch arm 60 to its other throw position.

For general control of the timing mechanism so that it may be operatedautomatically, manuall-y or stopped entirely, I provide a control .powerand transfer switch 12 which may be of a rotary type, examples of whichare well known to the art. As shown, this switch has an operating handle13 operative to three positions", respectively marked Automatic, Manualand Oil. The handle T3 is rigidly secured to a shaft indicated by thebroken line 14 and providedwith a. plurality of switching stagescom-prising contact arms 15 to 82, inclusive, of which T and 18aredouble-throw. The connection and arrangement of the severalswitchingstages are such that, when the handle T3 is in the automaticposition, the timer will be operated automatically by one of the motors28, 29-to run through its selective sequence of switching operations inthe times desired. If the handle T8 is in the manual position, then thetimer may be operated manually by suitable operation of the clutch andswitch operating handle 46'. If it is desired to stop the timerentirely, then the switch operating handle 13 is moved to the offposition. Since it may on occasion be desirable to use the driving motorto move one or more of the circuit controlling members 1 to a desiredposition without device operation before coming to such position, I' mayprovide a further control switching means 83 which, as shown, is of therotary type, examples of which are well known. to the art. This switchcomprises an operating handle 84 rigidly secured to and insulated from ashaft indicated by the broken line 84". To this shaft is rigidly secureda contact arm 85 movable to two positions or contacts, which may bedesignated N,,normal, and M, momentary. The handie 84 and. associatedparts are biased to the normal position against a stop by suitable.means indicated as a spring 86. The connection and arrangement of theswitch arm 85 and the contacts N and M are such that, in the normalposition, the timer may be operated either automatically or manually,but in the momentary position M, where the handle 84 must be held, thecircuit controlling members 1 can be move to a desired position by oneor the other of the motors '28, 19 when the handle 13 of the control andtransfer switch 12 is in the manual position.

In order to provide an alarm and also to prevent. operation of anydevice to be controlled, such as 6 in the event of failure of theimmediately preceding, device to function correctly, each device ismovidedwith suitable. switching means 81, such for example as a limit.switch. This switch 81: law arranged that, on failure of the priordevice to operate correctly, it remains closed to effectthe-energizationof a control andfalarm relays! atthe instant the circuit of the device 8is complated. This relay, through its circuit opening contacts as: andMy, disconnects the device and the motors 28 and 28 from. the busesX'and Y, respectively, opens its energizing circuit at its circuitopening contacts 90,. seals itself in through its circuit closingcontacts or, and through its circuit closing contacts 92 completes themet gizlng circuit of an alarm, such asa bell 93.

In acordance with my invention, I provide means for stopping anyone ormore of the cimuit control-ling members I on any desired associatedcon-tact segment or switch point and for maintaining such stoppage forthe time required to complete the operation under the control of thedevice which is energized when the circuit controlling membe'rreachesthe contact segmentin question. As illustrated in Fig. 2, thismeans for stopping a circuit controlling member 1 in a.- predeterminedposition and maintaining it there a given time comprises switchingmeans, such as a relay 94, which is connected to be operated-from aninitial position toa finalposition, when the circuit controlling member1' reachesthe predetermined circuit controlling position, to effect thedeenergization of the circuit of the motor 28 or 29 in service at thetime. For this purpose; the relay 94 is provided with circuit openingcontacts 95 in series with the energizing circuits of the motors 28 and26'. These circuits include a common portion identified on Fig. 2 as themain" timer motor circuit. Further in accordance with my invention, therelay 94' has its energizing winding 96 so connected as to be energizedwhen the'circuit' controlling member T reaches the predeterminedposition as, for example, when the lower circuit controlling memberengages the stationary contact segmentn;

Also in accordance with my invention, I provide means for preventing theenergization of the timer motor circuit for the desired predeter minedtime; As shown, this means comprises a movable element, such as a;circuit controller 91,, which is movable through a given range in thedesired predetermined :timeto effect at the end of said time thedeenergization of the relay 94 so as to causeth'e closing'of thecontacts in the main timer motor circuit. For this" purpose, the circuitcontroller 91 is arranged to open contacts 98"connected in series in thecircuit or the relay winding 96. As shown, these contacts 98 are mountedon an adjustably positioned arm 99' which is movable relatively to asuitably graduated scale I00 for setting the desired time delay.

For actuating the element 91 from' its initial position determined by astop I01 to which the element is biased by suitable means, such as aspring I02, suitable actuating or electromotive means, such as a motorI03, is arranged tobe energized when the circuit controlling member 1reaches the desired controlling position. For moving the element 91 at adesired. slow speed, there is provided suitable driving means, such as adifierential gear train I04, which is arranged to be placed in drivingrelationship withthe element 9-! while the circuit controlling member 1is in the predetermined controlling position. For establishing suchdriving relationship, there is provided an actuating connection, whichas. shown comprises a pivotally mounted clutch member I05 for holding agear MS of thedl'lferential train I'M against movement so as to-emeetrotation of the shaft I 01 on which the element 9? is rigidly mounted.This clutch or holding member I is biased to the holding position bysuitable means, such as a spring I08, but is arranged to be moved fromand held out of engagement with the gear I06 to interrupt the actuatingconnection by suitable means, such as a clutch releasing magnet I09, thewinding IIO of which is arranged to be energized from the buses X and Y.For controlling the energization of the clutch magnet I09, the circuitof its winding is arranged to include the circuit opening contacts IIIof a control relay II2 whose winding H3 is connected to be energizedwhen the movable circuit controlling member I in question reaches thedesired circuit controlling position for which a given sustained ordormant timing period is desired. For an indication of the condition ofenergization of the control relay I I2 and also the integrity of thecircuits of the dormant timer, there may be provided indicating means,such as a lamp II4, which is connected to be energized as long as themovable circuit controlling member 1 is in the desired circuitcontrolling position. For momentarily controlling the energization ofthe dormant timer, there may be included in circuit with the partsthereof a switch II5 mounted on and insulated from a shaft indicated bythe broken line H6 and arranged to be operated by a handle I I1 which isbiased to the switch closing :position by a spring II8.

For an explanation of the operation of the illustrated embodiment of myinvention, it will be assumed that the parts are positioned as shown inthe drawings, that is, with the control power and transfer switch 12 inthe automatic position and the clutch and motor selector handle 46 inposition to close its contacts 48 and 49 in the circuit of the motor 28and to clutch the gear mechanism 30 associated with the motor 28 so asto drive the bevel gears 26 and and thereby rotate the shaft 22. It willfurther be assumed that the lower circuit controlling member I has beenactuated to engage the stationary contact segment I2 in the circuit ofthe control device 6. Then, before this engagement of the lower circuitcontrolling member 1 with its associated contact segment I2, theenergizing circuit of the motor 28 was completed from bus X throughswitch arm 18, conductor I20, switch arm 16, conductor I2I, switch arm85, conductor I22, contacts 95 of relay 94, conductor I23, switch arm48, conductor I24, motor 28, conductors I25 and I28, contacts 89; ofrelay 88, conductor I21 and switch arm 15 to bus Y.

When the lower circuit controlling member I engages the contact segmentI2 and the impulse switch arm 54 engages the contact 51, as shown, thecircuit of the control device 6 is completed as follows: from bus Xthrough switch arm 18, conductor I28, contacts 89:1; of relay 88,conductors I29, I30 and 62, transfer switch arm 60, contacts 63,conductor 64, switch arm 54, contact 51, conductor I3I, switch arm 19,conductor I32, lower inner ring contact 9, contact I1, conductor 2Icontact I8, contact segment I2, conductor I33, device 6, conductor I26,contacts 891 of relay 88, conductor I21, and switch arm 15 to bus Y. Ifthe prior control device has failed to function correctly, its contacts81 will be closed. Accordingly, the relay 88 will be connected acrossthe buses X and Y substantially simultaneously with the device 6 througha parallel circuit from conductor I33 and including conductor I34through switch 81 and the contacts 90 of the relay 88. In the event thatthe relay 88 is energized, it will interrupt the circuit of the controldevice 6 at con tacts 89:: and 891 If, however, the buses X and Y areenergized and the relay 88 is deenergized, that is, switching device 81is open, then to indicate automatic control an indicator lamp I35connected in a circuit from bus K through switch arm 18, conductor I20,switch arm 16, conductor I36, lamp I35, conductor I31, contacts 89y ofrelay 88, conductor I21, and switch arm 15 to bus Y will be lighted.

Assuming now that the device 6 is one whose delayed or dormant period isto be controlled by the dormant timer arrangement shown in Fig. 2, then,upon completion of the circuit of the device 6 as heretofore traced, thedormant timer will be started in operation since the motor I03, theclutch control relay II2, the motor stopping relay 94, and theindicating lamp II4 will be simultaneously connected in parallel .withthe device 6 across conductors I38 and I26. Immediately upon the openingof the contacts of the motor control relay 94, the motor 28 stops withthe contacts I8 of the circuit controlling member 1 still on the contactsegment I2. Upon the opening of the contacts III of the clutch controlrelay II2, the clutch coil H0 is deenergized so that an actuatingconnection is established between the motor I03 and the controller 91when the clutch member I05 engages the gear I06. The controller 91 isthus started into operation and, after a predetermined time, opens thecontacts 98 in the circuit of the motor control relay 94, which closesits contacts 95 to again start the motor 28.

As soon as the impulse switch moves its arm 54 from the contact 51, themotor I03 and the clutch control relay H2 and the indicating lamp lI4are deenergized. Upon deenergization, the clutch control relay I I2closes its contacts III to interrupt the actuating connection betweenthe controller 91 and the motor I03. Consequently the dormant timercontroller 91 resets under the bias of the spring I02. It is to be notedthat this resetting action does not require the use of any additionaltimer contacts. The timing action of the main timer shown in Fig. 1continues in accordance with a predetermined schedule to control otherdevices, not shown, in the same manner as the device 6 is controlled andeither with or without the supplementary action of a dormant timer.

In case of loss of voltage at the buses X and Y, the clutch controlrelay I I2 will drop out to close its contacts I I I, but the clutchmagnet I09, of course, continues deenergized because of no voltage.Also, motor I03 is deenergized as well as th motor control relay 96.Inasmuch as the clutch control magnet I09 is deenergized, the actuatingconnection between the deenergized motor I03 and the controller 91 ismaintained so that the controller is not returned to its initial orstarting position but remains Just where it was when voltage failed.Upon restoration of voltage, the clutch control relay I I2 quickly opensits contacts III to prevent release of the clutch member I05, and themotor I03 is reenergized to continue the timing action of the dormanttimer from its intermediate position. Consequently, for momentary lossesin voltage, the dormant timer period is not materially changed becausethere is no reset of the controller 91. Of course, with the return ofvoltage, the motor control relay 94 is immediately reenergized todeenergize the main timer motor circuit and thereby prevent rotation ofthe circuit controlling member 1.

If there is more than one step in the process requiring the same delayedor dormant period, it will be apparent that a single dormant timer maybe used for all of these steps. Thus, for example, other contactsegments, such as II) in the lower group and I4 in the upper group, maybe connected to the conductor I38, as shown, so as to start the dormanttimer when the upper and lower circu'f t controlling members 1respectively engage the upper contact segment It and the lower contactsegment I8. It will be apparent that, in accordance with my invention,

other dormant timers may be used to take care 01' different delayedperiods and that such other timers can be connected, in a manner similarto the one shown, to correspond with the devices whose times-are to becontrolled by a shutdown of the main timer.

For manual operation, the operating handle 13 of the control andtransfer switch I2 is moved to the intermediate or manual position andthe motor and clutch control handle 46 to the manual position 52. Withthese changes in mind and the circuits and operation heretoforedescribed, the operation under manual control including the operation ofthe dormant timer will be apparent except, of course, that under manualcontrol the dormant timer will not automatically restart the main timerat the end of the delayed period.

For indicating the completion of the device control circuits from thebus X through the impulse switch, there are provided indicating lampsI38 and I48 respectively for the outer and inner rows of segmentalcontacts associated with the lower circuit controlling member I andsimilar indicating lamps I38 and I40 respectively associated with theouter and inner rows of segmental contacts associated with the uppercircuit controlling member I. The circuits of these lamps from the bus Xto the contacts 51 and 58 are the same as the device circuits to thesecontacts. The rest of the circuits of these lamps I39, I40, I39 and I40from the contacts 51 and 58 to the conductor I26 and thence to the bus Ywill be obvious by inspection. Also, an indicating lamp I35,corresponding to lamp I35 and similarly energized, may be provided forthe manual position of the control power and transfer switch I2. In thiscase, the circuit of the lamp I35 is from the bus X through the switcharm 18 in its lower position, conductor I28, contacts 891' of the relay88, conductor I29, switch arm '11 in its lower position, conductor MI,lamp I35, conductor I31, contacts 89y of the relay 88, conductor I21,and switch arm in its lower position to bus Y.

While I have shown and described my invention in considerable detail, Ido not desire to be limited to the exact arrangement shown, but seek tocover in the appended claims all those modifications that fall withinthe true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In combination, a timing device comprising a circuit controllingmember movable through a plurality of circuit controlling positions, amotor for effecting the movement of said member, an energizing circuitfor said motor, and means for stopping said member in one of saidpositions and maintaining it there for a predetermined time comprisingan electromagnetic switching means connected to be energized when saidmember reaches said one position and arranged when energized to effectthe deenergization of said motor energizing circuit, a movable elementfor eil'ecting the deenergizati'on of said switching means apredetermined time after said member reaches said one position and whilestill in said one position, electromotive means connected to beenergized while said member is in said one position, means forestablishing'an actuating connection between said electromotive meansand said element while said member is in said one position, and meansfor interrupting said actuating connection upon movement of said memberfrom said one position.

2. In combination, a timing device comprising a circuit controllingmember movable through a plurality of circuit controlling positions, amotor for effecting the movement of said member, a source ofelectromotive force, a circuit for energizing said motor from saidsource, means for stopping said member in one of said positions andmaintaining it there for a predetermined time comprising anelectromagnetic switching means connected to be energized from saidsource when said member reaches said one position and arranged whenenergized to eiiect the deenergization of said motor energizing circuit,means for deenergizing said switching means a predetermined time aftersaid member reaches said one position and while still in said oneposition comprising a movable element for efiecting the opening of thecircuit of the winding of said switching means, electromotive meansconnected to be energized from said source while said member is in saidone position, means tending to establish an actuating connection betweensaid electromotive means and said element, and electromagnetic meansconnected to be energized from said source and arranged to be controlledby said member to prevent the establishment of said actuating connectionexcept when the member is in said one position.

3. In combination, a timing device comprising a circuit controllingmember movable through a plurality of circuit controlling positions,motive means for efiecting the movement of said member, means forenergizing said motive means, means controlled by said member when themember reaches a predetermined one of said positions and arranged toeffect the deenergization of said motive means to stop the member insaid one position, and timing means responsive to said member reachingsaid one position for preventing movement of the member by said motivemeans from said one position for a predetermined time comprising anelement movable in one direction through a given range in saidpredetermined time and operative at the end of said range to effect thereenergization of said motive means and means for quickly moving saidelement in the opposite direction through said predetermined rangefollowing reenergization of said motive means.

4. In combination, a timing device comprising a circuit controllingmember movable through a plurality of circuit controlling positions,motive means for effecting the movement of said member, switching meansconnected to be operated from an initial circuit controlling conditionto a final circuit controlling condition when said member reaches apredetermined one of said positions and arranged to effect thedeenergization of said motive means to stop the member in said oneposition, and means operative while said member is in said one positionto prevent movement of the member by said motive means movement of saidmember, a source of electromotive force, means for energizing saidelectromotive means from said source, electromagnetic switching meansconnected to be energized from said source when said member reaches apredetermined one of said positions and arranged when energized toefi'ect the deenergization of said electromotive means to stop themember in said one position, and means connected to be energized fromsaid source while said member is in said one position operative toprevent movement of the member by said electromotive means from said oneposition for a predetermined time comprising a circuit controllermovable in one direction through a predetermined range in saidpredetermined time and operative at the end of said range to effect thedeenergization of said switching means whereby to eflect thereenergization of said electromotive means, means for quickly movingsaid controller reversely through said predetermined range uponreenergization of said electromotive means, and means for preventing thereverse movement of said controller upon failure of the voltage of saidsource while the controller is in an intermediate position.

ALRIC H. POWELL.

